In general, a catheter refers to a medical tube that is inserted into the body for drug delivery or that is used for discharging foreign substances from the body.
There are various types of catheters depending on the purposes thereof, which include, e.g., a urethral catheter inserted into the urethra to temporally discharge urine, a bronchial tube catheter used for discharging phlegm or saliva from the airway of the body, or a rectal tube catheter used for removing the foreign substances from the rectum.
Such a medical tube catheter is directly inserted into the body upon use, and thus, the material of the catheter needs to satisfy various conditions including flexibility, dimensional stability, and processability. Most of all, biocompatibility is critical for the medical tube catheter.
Natural latex has been widely used as the material of the conventional medical tube catheters.
Latex, a natural substance produced from the rub tree, is processed and used for up to 40,000 products including shoes, gloves, sportswear, and medical products, thanks to low price and relatively good physical properties. However, latex may cause allergies and contain a number of toxins. Accordingly, latex is disadvantageous in light of biocompatibility.
For example, a latex catheter, when directly contacting the human body, may cause skin allergies, such as dermatitis or rash, on the contacted region, or if inhaling latex-contained particles, one may have a sneeze, nasal discharge or congestion or other nasal inflammation or spasmodic dyspnea or cough. In severe cases, anaphylaxis (spasmodic dyspnea, chest compression, hypotension or shocks, etc.) may be caused, leading to a serious condition.
In particular, such catheter performs hole punching to facilitate drainage, and in this case, the catheter may directly discharge various toxins, affecting the human body.
As an alternative, there has been an attempt to replace latex with polyurethane, silicone, or synthetic polyisoprene (Korean Patent Application Publication No. 10-2011-0037929) as the material of the tube catheter.
However, polyurethane is relatively pricey, silicone suffers from low processability together with relatively high price, and synthetic polyisoprene is disadvantageous in light of price and is difficult to commercialize due to its material properties.
Meanwhile, as set forth in Korean Patent Application Publication No. 10-2000-22224 titled “medical equipment”), there has been an attempt to utilize PVC (polyvinylchloride) as the material of the catheter.
However, a plasticizer is additionally used to lower the hardness of the PVC material. Such use of the plasticizer may reduce the hardness of the PVC but may also lead the surface of the catheter to be sticky. Accordingly, such type of catheter is difficult to insert and remove from the body due to friction. Thus, the catheter is nearly impossible to use, and forced use of the catheter may damage the contacting region.
Further, in the above case, the hardness can be lowered by adding a plasticizer, but elasticity cannot be obtained, thus rendering it difficult to replace the conventional latex material therewith.